JPS6242314A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain correct tracking by using a tracking error signal to correct the relative position relation between a head and an objective track based on a signal obtained through plural prescribed operating gaps having the same azimuth angle in the head. CONSTITUTION:A head unit 1 has four head cores 2-5, the head cores 2, 3 have respectively the operating gaps 2a and 3a having a positive azimuth angle and the head cores 4 and 5 have respectively the operating gaps 4a, 5a having, e.g., a negative azimuth angle. A signal is recorded by a head core couple 2, 3 of the head unit 1 on odd number tracks T1, T3,... and by a head core couple 4, 5 on even number order tracks T2, T4,... respectively. In reproducing a signal of the 7th track T7 by the odd number order track head core couple 2, 3, the state B of the head unit 1 represents a correct tracking state and the correct tracking is executed by moving the head unit so as to obtain the state B where L2 and L3 are equal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recording/reproducing apparatus, and particularly to tracking control during reproduction.

(Prior Art) For example, in a recording/reproducing apparatus using a magnetic disk as a recording medium, the following means are used as means for tracking control during reproduction. That is, (1)! A servo track dedicated to tracking is set on the information recording surface of the optical disk or the opposite surface thereof, and when reproducing recorded information, a tracking signal is reproduced from the servo track and tracking control is performed based on this.

(2) Detecting the level of the playback signal when playing recorded information,
Tracking control is performed so that this is the highest.

etc.

(Problem to be Solved by the Invention) However, for example, in the above-mentioned method (1), a dedicated head for the servo track is required in addition to the head for recording and reproducing information; The mechanical structure of the machine has become larger and more complex, and the manufacturing process has become complicated, such as the need for highly accurate mechanical communication between the information-only head and the servo-only head, resulting in high costs. , it is not suitable for high-density recording because it has a servo track. On the other hand, although the above-mentioned method (2) solves this problem, on the other hand, the direction of the tracking error cannot be determined unless the head is moved in one direction across the track. If the recording level of the information signal is not stable, it will be difficult to determine whether the level fluctuation is due to a tracking error or a fluctuation in the recording level itself. There are theoretical disadvantages such as time consuming, and there is also the disadvantage that the control circuit itself becomes complicated.

The present invention has been made in view of the above-mentioned disadvantages, and is not limited to devices intended for magnetic disks.It has a simple configuration and is inexpensive, and can perform good tracking control. The object of the present invention is to provide a new recording/reproducing device particularly suitable for high-density recording.

(Means for Solving the Problems) In order to achieve the above object, the recording and reproducing apparatus of the present invention is divided into at least two parts. A recording/reproducing head having operating gaps having mutually different azimuth angles, and circuit means for forming a tracking error signal based on signals obtained through a plurality of predetermined operating gaps of the head having the same azimuth angle during reproduction. JAtn
It's something new.

(Function) '', when reproducing a recorded signal, the relative positional relationship between the head and the track to be reproduced is determined based on the signals obtained through the above circuit means through a plurality of predetermined operating gaps having the same azimuth angle of the head. A signal indicating this, that is, a tracking error signal, is obtained. Therefore, correct tracking can be performed by correcting the relative positional relationship between the head and the target track using this tracking error signal.

Incidentally, the reproduced information signal can be obtained through all the working gaps of the head having the same azimuth angle, and when recording information, it is possible to use all the working gaps in one. That is.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First of all, referring to FIG. 1, this figure shows a recording/reproducing magnetic head according to an embodiment of the present invention as viewed from the surface that contacts the medium. In FIG. 1, 1 indicates the entire head unit. The head unit 1 shown here includes four head cores (magnetic cores) 2 to 5, and the head cores 2 and 3 have working gaps 2a and 3a, respectively, of the same, e.g., positive azimuth angle, and these work Gap 2a and 3
The head cores 4 and 5 have working gaps 4a and 5a of the same negative azimuth angle, for example, and are joined so that the working gaps are in a straight line. It is joined. Note that the head cores 3 and 4 are arranged close to each other, and the four head cores 2
,3. and 5 are independently wound.

FIG. 2 shows an enlarged view of a recording track pattern of a recording medium, for example, a magnetic disk, when recording is performed using a head configured as described above.

Here, the odd numbered tracks T+, T3, ---1 are processed by the head core pair 2-3 in the head unit 1.
Furthermore, signals are recorded in the even numbered tracks T2, T4, . . . by the head core pair 4-5, respectively.

In this case, the head unit is fed by two track pitches. This also applies when reproducing recorded signals.

Next, the principle of tracking control in this embodiment using the head unit configured as described above will be explained with reference to FIG.

Figure 3 is an enlarged view of a part of the magnetic disk that is the recording medium.
This figure shows the relative positional relationship of the head unit (1) with respect to one recording track. In the figure, T indicates the recording track of the information signal, and those with odd numbered suffixes indicate the odd numbered tracks, and An even number means an even numbered track.

Now, if we try to reproduce the signal of the 7th track T using the odd-numbered track RAD core pair 2-3, in the figure,
The state of the head unit l shown by B indicates a correct tracking state, and at this time, the head core pair 2-3 is on-track with respect to the recording track TI, so that the respective reproductions obtained through both head cores 2 and 3 are Signal levels L2 and L3 are equal. On the other hand, the states of the head unit l shown by A and C indicate states in which correct tracking is not obtained. Therefore, both head cores are off track from track T7. Comparing the levels L2 and L3 of the respective reproduced signals obtained through A and 3, it is found that in the case of A, L2<L3. Conversely, in the case of C, L2
>L3. Therefore, when comparing the levels L2 and L3 of the reproduced signal, if L2<L3 (i.e., A), L2 increases, that is, the on-track amount of the head core 2 increases, and L2>L3 (i.e. C)
In this case, correct tracking can be achieved by moving the head units in the direction in which L3 increases, that is, in the direction in which the on-track amount of the head core 3 increases, so as to obtain state B in which L2 and L3 are equal. This is the translation.

Incidentally, the above also applies to the case where the signal of an even numbered track, for example, the eighth track T8, is to be reproduced by the RAD core pair 4-5 for even numbered tracks.

Therefore, when an odd numbered track is to be reproduced, the level of each reproduction signal obtained through the head cores 2 and 3 for the odd track is compared, and when an even numbered track is to be reproduced, the level of each reproduction signal obtained through the head cores 4 and 3 for the even track is compared. By comparing the levels of the respective reproduced signals obtained through the process, it is possible to perform tracking corresponding to each signal satisfactorily.

FIG. 4 shows an example of a circuit system based on the above-mentioned principle.

In the figure, for example, in the playback mode of odd-numbered tracks, both switches 7a and 7b in the switch circuit 7 are set to OFF.
(odd) side, so that on one circuit, the head unit (head unit) 1 is connected to the odd track pair 2-
3 will be selected.

In this state, each signal picked up by both head cores 2 and 3 in the head unit 1 from the magnetic disk 6 which is being rotated by a motor (not shown) is sent to the recording/playback switching terminal connected to the playback side (FB), respectively. The signal is inputted through each switch 8a and 8b in the switch circuit 8 to the reproduction preamplifiers 9a and 9b. The outputs of these reproduction preamplifiers 9a and 9b are respectively input to reproduction signal level detection circuits 10a and 10b having appropriate configurations such as a smoothing circuit, a low-pass filter, or an envelope detector, where the respective levels L2 and L3 are input. Detected. The outputs L2 and L3 of these level detection circuits 10a and 10b are input to the differential amplifier 11 in order to detect tracking errors, and the difference L2-L3 between the two is determined here, and this difference signal L2-L3 is used as rice planting. −Vref in accordance with the magnitude relationship with respect to the reference level ±Vref, which is determined to define a predetermined dead band for determining the substantially on-track state of the head core pair.

<L2-L3<+Vref, output Qs, L2-L3<Vref, output Q
A and is attached to the comparator 12 which makes the output Qc high when L2-L3>+Vref. Here, the high outputs of the comparator 12, Q8, Qs, and Qc correspond to the state iA of the head unit 1 explained in FIG.
, B, and C, respectively.

In accordance with the high output QA or Qc of the comparator 12 as described above, the tracking control circuit 13 operates the head moving mechanism including a step motor etc. through the drive circuit 14, and performs correct tracking of the head unit 1 as explained in FIG. In order to obtain the state fEj, the head unit) 1 is moved in the radial direction of the magnetic disk 6 as shown by the arrow X,
The movement of the head unit 1 is stopped when the output Q8 of the comparator 12 becomes high. In this way, a correct tracking state of the head unit 1 can be obtained.

For reproduction of even-numbered tracks, both switches 7a and 7b in the switch circuit 7 are connected to the E (ever) side, so that the Herad cores 4 and 5 are connected on the circuit.
The same operation as described above is performed for the even-numbered track that is connected and designated.

In addition, in the playback mode, the playback preamplifiers 9a and 9b
The outputs of are added in an adder circuit 16, then reproduced in a reproducing circuit 17, and a reproduced output is obtained at its output terminal 17a.

In the recording mode, the recording input applied to the input terminal 18a is processed for recording by the recording circuit 18, and then
The outputs from the recording preamplifiers 19a and 19b are simultaneously output to the recording preamplifiers 19a and 19b, and the outputs of these recording preamplifiers 19a and 19b are further connected to the switch circuit via each switch 8a and 8b in the recording/playback switch circuit 8 connected to the recording side (REC), respectively. Herad Core 2 in odd track recording mode due to 7.
and 3, and in the even track recording mode, is applied to the head cores 4 and 5, and recording is performed on the rotating magnetic disk 6h through each head core pair while forming one recording track.

An embodiment of the present invention is as follows.

(Modification) In the example of the head unit 1 shown in FIG. 1, the working gap with the same azimuth angle is divided into two (2a and 3a), but the number of divisions of the working gap with the same azimuth angle is 2.
It is not limited to , and may be 3 or more.

For example, when the number of divisions is 3, the tracking control of the head unit is performed in the same manner as in the above embodiment using the reproduction signal obtained through the head cores on both sides, while the reproduction output of the recorded information is from the center. A signal reproduced by a single Herad core or a composite (addition) signal of reproduced signals by three Herad cores is used, and in the recording mode, the same recording signal is commonly (and simultaneously) given to the three Herad cores. You can do it like this.

As can be understood from the above, when the number of divisions of a working gap with the same azimuth angle is n (however, n is a positive number of 2 or more), through a pair of symmetrical working gaps or the same number of working gaps with the same azimuth angle. It is sufficient to form a tracking error signal by comparing the levels of the obtained reproduced signals.

Further, in the above embodiment, when reproducing an odd numbered track, the signal from the rad core pair 2-3 is used for the odd numbered track, and
When playing back even-numbered tracks, tracking was performed using the signals from Radcore pair 4-5 for even-numbered tracks, but when playing back odd-numbered tracks, for example, track T7 in FIG. Radcore Vs 4
Tracking is performed based on the signal from track T8 obtained through track T8 through -5, and conversely, on the basis of the signal from track T7 obtained through rad core pair 2-3 for odd-numbered tracks during playback of track T8. You may also do this.

Furthermore, in the head unit 1 in the above embodiment, the azimuth angle of the working gap is set to two types, plus and minus, but it may be set to three or more types including zero. In that case, the feed of the head unit is adjusted according to the azimuth angle. The signal is multiplied by the amount corresponding to the type x track pitch, and tracking during playback can be performed using signals from a pair of head cores forming an operating cap having the same arbitrary azimuth angle.

In the embodiments described above, the recording signal may be of any type, such as a data (digital) signal, a video signal, an audio signal, etc.

Furthermore, although all of the embodiments described above were intended for devices that use magnetic disks as recording media,
The present invention is fully applicable to recording and reproducing apparatuses such as VTRs having a rotating magnetic head, and audio tape recorders that perform linear recording in the longitudinal direction of the tape using a magnetic tape.

Furthermore, from the viewpoint of miniaturization of the head unit, for example, FM
11 magnetic heads.

(Effects of the Invention) As described in detail above, according to the present invention, the structure is simple and inexpensive by basically devising the recording/reproducing head, and
There is a recording/reproducing apparatus that can perform good tracking control and can also cope well with guard panless high-density recording.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a recording/reproducing head unit according to an embodiment of the present invention, viewed from the side of the surface in contact with the medium. FIG. 2 is an enlarged view showing the recording pattern on the recording medium by the head unit of FIG. 1, FIG. 3 is a schematic diagram for explaining the principle of tracking control in an embodiment of the present invention, and FIG. 1 is a block diagram showing a circuit system of an embodiment of the invention. FIG. 1-m-recording/reproducing head unit, 2.3, 4.5--head core or magnetic core, 2a,
3a, 4a, 5a--one working gap. 6--Magnetic disk 10a, 1Ob--Reproduction signal level detection circuit, 11-
-1 differential amplifier, 12-m window comparator, 13-1 tracking control circuit, 15--head moving mechanism.

Claims (1)

[Claims] A recording/reproducing head, each divided into at least two parts, having a plurality of working gaps having different azimuth angles, and a signal obtained through a plurality of predetermined working gaps having the same azimuth angle of the head during reproduction. 1. A recording/reproducing device comprising circuit means for originally forming a tracking error signal.